.global _start


_start:

LDR R1, =0xFFFFFFFF
LDR R0, =0X00000000
LDR R3, =0X020C406C

@使能GPIO1的时钟
STR R1,[R3]

@屏蔽其他时钟
LDR R3, =0X020C4068
STR R1,[R3]

LDR R3, =0X020C4070
STR R1,[R3]

LDR R3, =0X020C4074
STR R1, [R3]

LDR R3, =0X020C4078
STR R1, [R3]

LDR R3, =0X020C407C
STR R1, [R3]

LDR R3, =0X020C4080
STR R1, [R3]

@配置复用寄存器到GPIO功能
LDR R3, =0x020E0068
LDR R4, =0x5
STR R4, [R3]
@配置GPIO01_03的电气属性
@LDR R4, =0X10B0
LDR R4, =0x38
LDR R3, =0x020E02F4
STR R4, [R3]

@配置GPIO功能的属性：
LDR R3, =0x0209C004
LDR R4, =0x00000008
STR R4, [R3]

LDR R3, =0x0209C000
STR R0, [R3]
